The contribution of Apoliproprotein E genetic variation to dementia risk in British South Asians

INTRODUCTION: Understanding the genetic basis of dementia in diverse populations is essential for ensuring that efforts to predict, prevent, and treat dementia are equitable. METHODS: We analysed data from 51,104 volunteers in Genes & Health - a cohort study of British South Asians - who have undergone genotyping and consented for healthcare record linkage. APOE genotypes were defined using phased, imputed genotype data. Cox proportional hazards models were used to assess the relationship between APOE genotype and dementia. Population attributable fractions were calculated for each APOE genotype. RESULTS: APOE ε4 was associated with all-cause dementia in a dose-dependent fashion (Cases=614, Controls=50,490; APOE ε4/ε4: Hazard Ratio 2.7, P<0.0001). The proportion of dementia cases attributable to this allele was 14.2% (95% CI -2.8% - 25.0%). DISCUSSION: APOE ε4 - the major genetic risk factor for sporadic dementia in European-ancestry populations - has a similar impact on dementia risk in British South Asians.